Write a short note on the doubly circular linked list.

Introduction

A Doubly Circular Linked List is a more complex type of linked list which contains a pointer to the next as well as the previous node in the sequence. Therefore, it consists of three parts: data, a pointer to the next node, and a pointer to the previous node. Unlike simple linked lists, the last node in a doubly circular linked list points to the first node (via its 'next' pointer) and the first node points to the last node (via its 'prev' pointer). This forms a circular loop.

Detailed Explanation

Properties of a Doubly Circular Linked List

1. Each node in a doubly circular linked list has a data part and two pointers, one points to the next node and the other points to the previous node.
2. The 'next' pointer of the last node points to the first node.
3. The 'prev' pointer of the first node points to the last node.
4. It can be traversed in both forward and backward directions.

Structure of a Node

The structure of a node in a doubly circular linked list is as follows:

struct Node {
    int data;
    struct Node* next; // Pointer to next node
    struct Node* prev; // Pointer to previous node
};

Here, 'data' represents the data part of the node, 'next' is a pointer that points to the next node in the list, and 'prev' is a pointer that points to the previous node in the list.

Operations on Doubly Circular Linked List

Insertion

Insertion in a doubly circular linked list can be done in three places: at the beginning, at the end, or in the middle. The steps for insertion at the beginning are as follows:

1. Create a new node.
2. Point the 'next' pointer of the new node to the first node.
3. Point the 'prev' pointer of the new node to the last node.
4. Update the 'next' pointer of the last node and the 'prev' pointer of the first node to the new node.

Deletion

Deletion in a doubly circular linked list can also be done in three places: from the beginning, from the end, or from the middle. The steps for deletion from the beginning are as follows:

1. Point the 'next' pointer of the last node to the second node.
2. Point the 'prev' pointer of the second node to the last node.
3. Delete the first node.

Traversal

Traversal in a doubly circular linked list can be done in both forward and backward directions. The steps for forward traversal are as follows:

1. Start from the first node.
2. Print the data part of the current node.
3. Move to the next node by using the 'next' pointer.
4. Repeat steps 2 and 3 until you reach the first node again.

Comparison with Other Data Structures

Applications of Doubly Circular Linked List

Doubly circular linked lists are particularly useful in applications where we need to go back and forth in our data. For example, they can be used in the implementation of a music player where we can go to the next or previous song. They can also be used in the implementation of a browser where we can go to the next or previous page.

Conclusion

In conclusion, a doubly circular linked list is a complex but powerful data structure that allows for efficient operations in both forward and backward directions. However, it also requires more memory due to the use of two pointers in each node. Despite this, its ability to easily navigate in both directions makes it a valuable tool in many applications.

Summary

A doubly circular linked list is a more complex type of linked list that contains a pointer to the next as well as the previous node in the sequence. It consists of three parts: data, a pointer to the next node, and a pointer to the previous node. The last node in a doubly circular linked list points to the first node, and the first node points to the last node, forming a circular loop. It can be traversed in both forward and backward directions.

Analogy

A doubly circular linked list is like a circular train track where each train car has a connection to the next car as well as the previous car. The last car is connected to the first car, creating a loop. This allows the train to travel in both forward and backward directions.